Arc-lamp.



No. 896,698. PATENTED AUG. 19, 1908. 0. P. STEINMETZ 9 J. T. H. DEMPSTER.

ARC LAMP.

APPLICATION FILED NOV. 16, 1903.

2 SHEETS-SHEET 1.

' Inventors.

Charles. P. Steinmetz,

John T. HDern peter; 0 Q

No. 896,698. PATENTED AUG. 18, 1908. G. P. STEINMETZ &'J. T. H. DEMPSTER.

ARC LAMP. APPLICATION FILED NOV. 16, 1903.

2 SHEETSSHEET 2.

Inventors: Charles P. .Steinmetz' Witnesses ster p I JohnT. De

PAENT in.

CHARLES P. STEINMETZ AND JOHN T. H. DEMPSTER, OF SOHENEOTADY, NEW YORK, ASSIGN- ORS TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

ARC-LAMP.

Specification of Letters Patent.

Patented Aug. 18, 1908.

Application filed November 16, 1903. Serial No. 181,328.

lamps in which but one of the electrodes is movable and in which the electrodes employed give a flaming or luminous are, although all of the features of our invention are not limited to such lam For a better understand ing of our invention reference may be had to the accompanying drawings in which we have illustrated an embodiment of our invention.

Of the drawings, Figure. 1 is an elevation of an arc lamp with the casing and the globe artially broken away and in section; Fig. 2 1s a sectional elevation of the lamp with the casinglremoved Fig. 3 is a diagram illustrating t e arrangement of the circuits of the lamp Fig. 4 is a sectional elevation of a portion of the upper art of the lamp upon an enlarged scale, and Fig. 5 is a diagram showing a modified arrangement of the circuits of the lamp.

Referring to the drawings, 1 represents a platform ca or top member from the upper side of whic extend a pair of parallel rods or members 2. These rods are connected at their upper ends by a bowed cross-head member 3, to the upper side of which suitable supporting means, as a ring 4, is secured. At some distance below the platform 1 is located a circular late or platform 5. Y A air of vertical tubu ar magnet coils'6 are ocated between the platform or top '1 and the plate 5. The plate 5 is supported from the member 1 by bolts 7 and the magnet coils 6 are clamped in place. by these bolts. "The rods 2 ma be threaded into the upper end pieces of t ese magnet coils as'shown in Fig. 2. Posts 8 secured at their upper ends to the plate or latform 5 carry at their lower ends a circuar platform 9. An annular member 10 of substantially the same outside diameter as the platform 9 is secured to the latform 9 by bolts 11. The platform 9 an the annular member 10 are separated by bushings or collars 12 which surround the bolts 11.

About midway between the platform 9 and the annular member 10 is located a plate 13 which is secured to the platform 9 by bolts or screws 14. The plate 13 is insulated from the latform 9, suitable washers and space bloclfs of insulating material being employed to insulate the bolts 14 from the platform 9. From the under side of the plate 13 extends a rod or encil 15 which forms the upper electrode o the lamp. The rod 15 and the plate 13 should be formed of some material such as copper which is a good conductor both of heat and electricity. The rod and the plate may be formed integrally with one another or the rod may be provided with a threaded extension '16 on its upper end which is screwed into a threaded aperture formed for the purpose in the plate 13.

- The pencil 15 may be surrounded, except at its lower end, by a tube 17 of mica, or the like. This in turn is preferably surrounded by a tube or jacket 18 of some material which is non-conducting, and which is unaffected by high temperature, such as porcelain. As shown in Fig. 2 the tube or jacket 17 extends from the plate 13 to within a short distance of the lower end of the pencil 15. The tube 18 extends from the plate13 slightly farther than the tube 17 but still not so far as the pencil 15. This arrangement insures an annular space 18 between the lower end of the tube 18 and the pencil 15. A tubular member 19 of considerably greater internal diam-' eter than the external diameter of the tube 18 is secured to the under side of the annular member 10 at its inner periphery, and extends downward about as far as the pencil 15 which is centrally located in it.

A removable cylindrical member 21 extends between the outer peripheries of the platform 9 and the annular member 10. plurality of apertures 22 .are formed in this cylindrical member for a purpose to be hereinafter set forth.

The armature which cooperates with the tubular magnet coils 6 comprises a pair of rods or bars 23 of magnetic material which are connected at their lower ends by a cross bar 24 also of magnetic material A rod or bar 25 secured at its lower end to the middle of the bar 24 passes upward through apertures formed for the purpose in the platforms the 1 and 5. The upper end of this bar is connected by means of a cotter pin 26 with the plunger 27 of a dash-pot. The shell member 28 of the dash-pot which surrounds the plunger member is pivotally secured to the lower end of a threaded bolt 29 by a cotter pin 30. To one side of the shell 28 is adjustably secured a bar or. arm 31. The said bar is formed at its lower end with an offset portion 32 which is adapted to engage the enlarged portion 33 of the plunger 27 to prevent its moving farther out than is shown in Fig.2.

The upper end of the bolt 29 passes slidingly through an aperture formed for the purpose in a bow-shaped member 34 and carries on its upper end a nut 35. The ends of the bow-shaped member 34 are secured to a hollow or box-like frame 36 which slidingly embraces the rods 2, as is clearly shown in Figs. 2 and 4. A pair of pawls or dogs 37 are pivotally secured between the side walls of the frame 36. The outer ends of the dogs 37 are adapted to engage the rods 2 and'thereby lock the frame and the rods together when the inner ends of the dogs are depressed. The inner ends of the dogs are enlarged and are formed with upper and lower knife edges 38. These play between the nuts 39 and 40 which are adjustably mounted on the threaded rod 29. A helical spring 41 surrounds the bolt 29 between the bowed member 34 and the nut 39.

The nut 39 is so adjusted on the rod 29 that by its engagement with the upper knife edges 38 under the action of the spring 41 it ho ds the dogs 37 in such a position that they look the frame and the rods together. When however the rod 29 is forced upward the nut 40 engages the lower knife edges 38 and causes the pawls to be disengaged from the rod, in consequence of which the frame and bolt. When this upward pressure is exerted upon the bolt 29 the spring 41 is compressed to allow the necessary movement between the bolt and the frame.

A bar 42 secured to the under side of the bar 24 supports a pair of depending parallel rods or bolts 43. The rods or bolts 43 carry at their lower end a cross-head or bar 44 on which a socket 45 is mounted. The lower electrode 46 of the lamp is placed in this socket.

To the under side of the platform 1 is secured the upper leg of a U-shaped bar 47 of conducting material such as copper or brass. Below the up er leg of the U-shaped bar 47 is secured an e ectromagnet 48. The electromagnet 48 comprises a cylindrical core 49, an end piece 49, a yoke member 50, the armature 51 pivoted thereto, and a" winding 52. The members 49', 50 and 51 are formed of magnetic conducting material. The member 50 is insulated from the member 47 which in turn is insulated from the platform 1.

pawl are free to travel upward with the eeaees The lower leg of the U-shaped member 47 has a threaded opening formed in it in which is mounted a contact member 53. This contact member is normally in engagement with a contact portion on the under side of the armature 49. A helical spring 54, having one end secured to the under side of the armature and the other end secured to one end of an adjusting screw 55 supported by a bracket 56 carried by one of the bolts or posts 7, assists gravity in forcing the armature 51 down against the contact screw 53.

The lainp mechanism located between the platforms 1 and 9 is inclosed by a cylindrical casing 57 formed out of some suitable mate rial, such as sheet metal. Bracket arms 58 secured to the under side of the annular member 10 carry screws 59 which detachably hold in place an inclosing globe 60, formed of til'ansparent or translucent material, such as g ass.

The circuit connections of the lamp are indicated in Fig. 3, where 61 and 62 represent tinge terminals of the lamp. A conductor 63 le ds from the terminal 61 to the lower electrode 46 of the lamp. One terminal of the winding of the magnets 6 is connected to this conductor between the terminal 61 and theelectrode 46 at the point 64. A conductor 65 leads from the other terminal of the windings of the coils 6 to the binding screw 66 carried by the U-shaped member 47. A conductor 67 leads from the terminal 62 to a binding screw on the yoke member 50.'

en the armature 51 is in the position shown in Fig. 1- and Fig. 3, an electrical con- V nection exists between the lines 65 and 67 through the U-shaped member 47, armature 51, and yoke member 50. This circuit is broken when the armature 51 is pulled up against the core 49. One terminal of the magnet coil is connected to the yoke member 50 and thenbe through the conductor 67 to the terminal 62. The other terminal of this coil is connected to the late 13, which is in electrical connection wit the electrode 15.

The mechanism -is-s"hown in, the drawings in the position which it assumes when the lamp is out of circuit. When the terminals 61 and 62 are connected to a roper source of electrical energy current will flow from the terminal 62 through the conductor 67, yoke member 50, armature 51 contact screw 53, yoke member 47 conductor 65, magnet windings to the point 64, and then through the conductor 63 to the terminal 61. The passage of current through the magnet windings causes the armature to be attracted, lifting the lower electrode 46 into en agement with the electrode 15. The u ward movementof the rod 25 occurring at t e same time causes the plunger 27 to be moved upward in the shell 28 until it strikes the top of the shell. Any further upward movement of the rod 25 necessary to bring the electrode 46 into enseats When the electrodes 15 and 46 contact current will begin to flow between them in a circuit which comprises conductor 67, wind ings 48, plate 13, electrode 15, electrode 46 and conductor ,63. The passage of current through the windings 48 will cause the armature 51 to be attracted and lifted out of en-- gagement with the'screw 53, thus breaking the circuit, which includes the windings of the magnet coils. When this occurs the armature will no longer be attracted but will begin to descend under the action of gravity, the dogs 37 will again lock 'the frame 36 to the rods 2, the electrode 46 will move away from the electrode 15 and. an arc will be drawn between the electrodes. The distance which the electrode 46 moves away from the electrode 15 under the circumstances is equal to the amount of travel which the dash-pot plunger 27 has in the shell 28 from its extreme upward position to the point Where the enlargement 33 is engaged by the offset portion 32 carried by the arm or bar 31. This distance, which can be varied by adjusting the arm 31, is thus equal in length to the arc struck after each feeding operation in the normal operation of the lamp.

Whenever the arc goes out, as by opening the main circuit, and the lamp is again put in circuit, the feeding operation will be repeated. The upward movement of the frame 36 occurring after the lungers2 7 engages the upper part of the she l 28 will be suflicient of course to compensate for the shortening of the electrode 46 produced by the consumption since the preceeding feeding operation. When the magnet windings are again deen ergized by the actionof the electromagnet 48 and the armature begins to descend, the dogs 37 will immediately engage the rods 2, locking the frame and rods together and an arc will again be struck between the electrodes 46 and 15 equal in length to the movement of the plunger 27 in the shell 28.

It will be observed that with the feeding mechanism described the electrodes do not move together when the lamp is out of service. This is sometimes quite desirable as, for instance, where one or both of the electrodes are formed of material which becomes plastic when heated. In this case the electrodes areliable to weld together if they move into contact with each other while in a plastic condition.

The lamp which we have hereinbefore described andillustrated in detail is particularly adapted for use where the electrode 15 is thepositive electrode and is formed out of some conducting material, such as copper, which is intended to be unconsumed in the operation of the lamp. It has been found desirable that this electrode be connected to a plate, such as plate 13 shown, which is of cod heat-conducting material, in order that it may add to the heat-dissipating capacity of the electrodeand thus keep its temperature at a point which will preserve the electrode from consumption.

The lower electrode employed in the particular lamp shown and described in detail is intended to consist of or contain some material such as the magneticoxid of iron, titanium carbid, or similar material which is characterized by the fact that it gives a luminous orflaming arc and which is. also char acterized by the fact that it is but very slowly consumed in the 'o eration of the lamp.

We have foun that electrodes of this character can be constructed in which the rate of consumption is so slow that the increase of arc length occurring in the normal period of operation of the lamp is so slight as not to require a feeding movement of the lamp mechanism during such period. For that reason the particular lamp which we have illustrated and described in detail is intended to run without altering the position of either electrode after starting during the normal period of operation of the lamp. Whenever the circuit of the lamp is interrupted a feedin operation will of course take place, and it is t ought that this arrangement will be sufficient for many purposes. When, however, it becomes necessary to provide lamps which operate continuously or in which the consuming electrode has a rate of consumption great enough to require a feeding movement of the electrode at intervals during the normal period of operation, it will only be necessary to add means such as a coil in shunt to the are which will close a temporary shunt about the windings of the electromagnet 48 or otherwise denergize it whenever the volta e of the arc rises above a predetermined vafiue, or to interrupt the supply of current at the supply station when the voltage of the circuit rises unduly in a constant current system or at any desired interval of time.

Means for denergizing the electro-magnet 48 for the pur ose of securing the feeding movement of t e electrode at intervals during the normal period of'operation of the lamp are indicated in Fig. 5. In this drawing 18 shown an electro-magnet 67 provided with a high resistance winding in a shunt 6869 around the arc. The armature 70 of this electro-ma et, when attracted, short circuits the win ing of the electro-magnet 48, and this occurs whenever the voltage of the arc rises above a pre-determined value. Under these conditions the armature 51 of the electro-mag'net 48 drops and makes contact with the tip of the screw 53, so that the current of the ma net 48, by the yoke 47, conductor 65 through the windings 6, so that a new are of normal length is started. The volta e across such are is insuificient to divert sufficient current to the high resistance winding of electro-magnet 67, to hold up its armature, which is therefore released, thus breaking the short circuit around the electro-magnet 48.

In the operation of the lamp more or less of a draft will be caused through the tubular member 19 which will steady the arc and carry the products of combustion, diluted more or less by air coming in at the upper edge of the inclosing globe 60, into the space between the platform 9 and the annular member 10, and thence through theapertures 22 out into the atmosphere. I

The products of combustion from a lamp in which the consuming electrode contains the materials specified above will, in some cases at least, not be ermanent gases like most of the roducts of the are between carbon electro es but will be gases or vapors from which solid matter will condense upon suitable condensing surfaces. For this reason it is desirable to make the member 21 detachable so that matter which may condense in the chamber inclosed by it may be readily removed.

- Surrounding the electrode 15 by insulation which is not affected by the tem erature produced is an important feature in amps of this character, as it revents the are from wandering up the si e of the electrode, a thing which might otherwise occur, especially on account of the more or less non-conducting deposits which will be made from time to time u on the electrode from the arc.

Whi e we have herein described and illustrated somewhat in detail one embodiment of our invention, it is not intended that our invention in all its as ects shall be limited to this particular embo iment, as it will be apparent to any one skilled in the art that many changes may be made in the form of our invention without departing from its spirit. 7

What we claim as new and desire to secure by Letters Patent of the United States, is,-

1. In an arc lamp, an electrode arranged to be moved in one direction by gravity, electromagnetic means for moving the electrode in the opposite direction, and means for causing the electrode when moved under the action of gravity to travel through a predetermined fixed distance.

2. In an arc lamp, an electrode arranged to be moved in one direction by gravity, means for causing such movementto be always through a fixed distance, and electromagnetic means arranged to move said electrode in the opposite direction through variable distances.

3. In an arc lamp, a pair of electrodes one of them arranged to be moved away from the other by the action of gravity, means for limiting such relative movement to one through a fixed distance, and electromagnetic means arranged to move said electrodes toward the other until they come into engagement.

4. In an arc lamp, a air of electrodes one of which is arranged to e moved away from the other through the action of gravity, means for limiting such movement to one through a fixed distance, and electromagnetic means for moving said latter electrode toward the other electrode.

5. In .an arc lamp, an electrode arranged to be moved in one direction out of contact with the other electrode under the action of gravity, means for limiting such movement to one through a predetermined distance, electromagnetic means for moving. said first electrode in the opposite direction into contact with the other electrode to cause current to flow through'the electrodes, and means for deenergizin said electromagnetic means while current fiows through the electrodes.

6. In an arc lamp, a pair of electrodes one of them arranged to be moved away from the other under the action of gravity, means for limiting such movement to' one through a fixed distance, electromagnetic means for.

moving said electrodestoward each other,

and means for denergizing said electromagnetic means during the time current flows throu h the electrodes.

an arc lamp, an electrode, a second electrode arranged 'to be moved under the action of gravity away from the other ,elec trode to strike an arc, means for limiting such movement to one through a fixed distance, electromagnetic means for moving said latter electrode through distances sufficient to bring it into engagement with the other electrode, and means for maintaining said electromagnetic means denergized while current flows through the electrodes.

8. In an arc lamp, an electrode arranged to be moved under the action of gravity in one direction, an electromagnet for moving it in the opposite direction, and clutch and stop mechanism arranged to limit the movement of the electrode in the gravity-controlled direction to one through a fixed distance.

9. In an arc lamp, an electrode, an electromagnet for lifting said electrode through variable distances, and means for permitting the electrode to drop thereafter through a predetermined fixed distance.

10. In an arc lamp, an electrode, an electromagnet for lifting said electrode through variable distances to cause current to flow through the electrode, means for permitting the electrode to drop thereafter through a predetermined fixed distance, and means for eeaees maintaining said electromagnet denergized while current flows through the electrode.

11. In an arc lamp,a stationary electrode, a movable electrode, an electromagnet for moving said latter electrode into engagement with the stationary electrode to cause current to flow between the electrodes, means for denergizing the electromagnet during the time current flows through the electrodes, and means for permitting the movable electrode to travel away from the stationary electrode through a predetermined, fixed distance upon the denergization of the electromagnet.

12. In an arc lamp, a non-consuming electrode, a consuming electrode, an electromagnet for moving one of said electrodes toward the other to cause current to flow through them, means for denergizing said electromagnet during the time current flows through the electrodes, and clutch mechanism for permitting the movable electrode to travel under the action of gravity a predetermined distance awayfrom the other electrode upon the denergization of the electromagnet.

13. In an arc lamp, a pair of electrodes, electromagnetic means for moving one of said electrodes towards and in contact with the other to cause current to flow between them, and means for causing the first of said electrodes to travelaway from the other a predetermined" distance under the action of current to flow between them, and means for causing said electrodes .to thereafter be separated a fixed distance inde endently of the electrical conditions of the amp.

15. In an arc lamp, a pair of electrodes, electromagnetic means for moving one of them towards the other to cause current to flow between them, and means for causing the electrodes thereafter to be separated a fixed distance and to remain stationary until the arc is interrupted.

16. In an arc lamp, an electrode arranged to be moved in one direction by gravity, an electromagnet for moving it in the opposite direction, and means for limiting one of the movements of the electrode to a movement through a predetermined fixed distance independent of the amount of the other movement.

In witness whereof, we have hereunto set our hands this 7th day of November, 1903.

CHARLES P. STEINMETZ. JOHN T. H. DEMPSTER.

Witnesses:

BENJAMIN B. HULL, HELEN ORFORD'. 

